NOTICE TO PERSONS RECEIVING THIS DRAWING
AND/OR TECHNICAL INFORMATION:
Title:
TUNING PROCEDURE
TR4022
Checkp oint Systems claims proprietary rights to t he material disclosed hereon.
This drawing and/or technical information is issued in confidence for engineering
information only and may not be reproduced or used to manufacture anything
shown or referred to hereon without direct written permission from Checkpoint
Systems to the user. This drawing and/or technical information is the property
of Checkpoint Systems and is loaned for mutual assistance, to be returned
when it s p urp ose has been served.
THIS DRAWING AND/OR TECHNICAL INFORMATION IS THE
PROPERTY OF CHECKPOINT SYSTEMS, INC.
CHECKPOINT SYSTEMS, INC. CONFIDENTIAL AND PROPRIETARY INFORMATION, FOR INTERNAL USE ONLY.
Rev. 00Page 2
1.0I N TRODUCTION
This document describes the procedures required to properly tune a Strata System with the
TR4022 board. Many of the adjustments for the Strata are pre-tuned during the manufacturing
test process therefore adjustments required in the field have been minimized.
Adjustments such as center frequency and sweep are preset for 8.2 Mhz operation. If the system
is required to detect a different frequency tag the sweep range will need to be readjusted by the
installer.
Once properly configured, if poor performance results, the CSE should direct their efforts toward
finding the source of the interference in the environment. Several test signals are provided by the
TR4022 board, which may be viewed on an oscilloscope. These signals allow the CSE to identify
and measure ambient noise levels, resonances and other sources of environmental interference.
The DSP (digital signal processor) system automatically subtracts stationary resonances seen by
the antennas. The system offers flexibility to adjust for these circumstances. However, the
solution for environmental problems, is to determine the environmental problems and resolve
them. The options for adjusting to environmental problems are performed both in the analog and
digital realm by the technician. The analog solutions are reducing power on the transmit antennas
(2-loop and/or 3-loop), reduce the baseband gain, and adjust the sweep. In the digital toolbox
there are four user selectable filter parameters. These tools should be used only after the CSE has
attempted to correct the environment.
TUNING PROCEDURE TR4022
The Strata system is powered by a +24Vdc power supply, P/N 121878. This power supply can
power up to a maximum of three antennas.
2.0SYSTEM DESCRIPTION
The Strata system is a transceiver design using both a 3-loop, 2-loop, and a 1-loop antenna design.
The Strata alternates between using the 2-loop antenna and the 3-loop antenna. The 1-loop
antenna is used as a shield that is tied to ground. This technique provides the system with
different views of the detection field allowing the system to improve detection by minimizing the
holes typically found at the crossbars of typical swept antennas.
During an antenna’s cycle, the system performs two “blasts” which are called a “bin”. There are
sixteen bins per frame. A bin consists of two “noise” cycles and two blast cycles, a blast is a
transmit cycle and then a receive cycle. During the noise cycle, the system is not transmitting,
only receiving ambient noise. This allows the system to establish the baseline noise level of the
environment for later comparison. The system then transmits or “pulses” the field and then
receives or “listens” for an echo of a tag signal. This frame is repeated on the other antenna. A
tag response need only be present on one of the antennas to cause an alarm. In effect the system
provides the best of both worlds, a 2-loop and 3-loop design.
CHECKPOINT SYSTEMS, INC. CONFIDENTIAL AND PROPRIETARY INFORMATION, FOR INTERNAL USE ONLY.
Rev. 00Page 3
The switching between antenna loops minimizes the size of detection holes at the null points of
the RF field.
3.0SWITCH SETTINGS
Table 1 explains each of the jumpers on the TR4022 board and 4.0 explains the switches on the
TR4022 board that must be configured before the system will operate. The illustrations on the
next pages shows the position of the jumpers, switches, and potentiometers on the TR4022 board
used during configuration. The top of the shield is held with 4 thumb turn screws. With the top of
the shield removed all the switches can be set without removing the electronics from the antenna.
If for some reason the circuit board needs to be removed from the antenna housing, remove the
three mounting screws from the backside of the board housing. Removing the rear cover of the
antenna assembly can access them. Before completely removing the electronics package from the
antenna loosen the screw near the TX1 and TX2 antenna connector and remove the spade lug.
MAKE SURE WHEN REINSTALLING THE ELECTRONICS PACKAGE THAT THE SPADE
LUG FROM THE SHORTED TURN IS REINSTALLED IN THE SAME PLACE.